Clickers are the third stage of the Infected that have had prolonged exposure to the fungus. They are completely blind, but maneuver through areas using echolocation, which produces the clicking sound that they are named after. They appear to be much less human than Runners, with faces that are skewed and scarred by fungus growing out of their infected brains, out of their eye sockets and over/around the head. They are also much more aggressive than Runners, and do not resist the fungus anymore because their humanity is now completely destroyed.

When a Clicker is provoked, the Clicker will enter a "berserk mode," aggressively flailing their arms. At this point, if a victim is caught in their arms, they will have a death grip and be able to feed on the victim if they do not have a shiv or are not helped by another survivor. There is no melee move to override this attack and the clicker will not flinch when shot with non-shotgun rounds if not aiming for the head. To counter this move, it is advised to keep good distance and wait for the Clicker to wear out, then try to hit it before it does another berserk. This can be done, or just try to shoot it before it gets to the player or to throw a molotov or scorch it with a flamethrower.

Clickers are relatively slow, and because of their blindness and crude version of echolocation, they can be easily outran as a result, eventually making it confused and try to click in all directions. However, if they manage to catch a survivor they will almost certainly kill them with ease, unless the victim is helped by another survivor or manages to stab the clicker with a shiv. However, one cannot shiv the clicker if it attacks from behind. Clickers can be briefly stunned if they are hit with a brick or bottle, making it vulnerable to attack with a melee weapon.